This invention generally relates to vehicle impact detection. More particularly, this invention relates to a system and method for utilizing information gathered from sensors on a vehicle to determine the type of impact and a desired resulting control.
Various devices have been incorporated into vehicles to prevent or minimize injury during impact or collisions. Supplemental restraint devices, including airbags for example, require control arrangements for processing information about impact events and appropriately controlling the supplemental restraint devices.
A recent trend has been to incorporate more electronically controlled peripheral devices on a vehicle and to control such devices using a single electronic controller. This presents several challenges and difficulties. For example, a given microprocessor may not have the bandwidth necessary to accomplish all of the processing and calculation necessary to achieve desired control of the various peripheral devices. To avoid utilizing more complex or expensive processors, alternative strategies and algorithms are required to achieve the desired overall performance.
This invention provides an improved approach to processing information from impact detection sensors that allows a controller to more easily determine the nature of impact and then accordingly control a supplemental restraint device such as an airbag.
In general terms, this invention is an impact detection system for use on a vehicle.
In one example use of this invention, at least one front sensor is positioned near a front portion of the vehicle. At least one tunnel sensor is positioned near a central location on the vehicle. A controller communicates with each of the front sensor and the tunnel sensor and determines an impact condition based upon determining whether a difference between a front sensor velocity and a tunnel sensor velocity exceeds a difference threshold.
The inventive system uses various pieces of information gathered or derived from the front sensor and tunnel sensor in addition to the determined difference between the front sensor velocity and the tunnel sensor velocity to determine the type of impact condition and to responsively provide control for a supplemental restraint device such as an airbag.
A method of controlling the operation of a supplemental restraint device according to this invention includes determining a front sensor velocity and a tunnel sensor velocity. A difference between the sensor velocities is compared to a difference threshold to determine when an impact condition has occurred that may warrant activating a supplemental restraint device.
According to this invention, different variables can be used in several combinations to address at least three distinct impact conditions to enable the desired control of the airbag or other supplemental restraint device.
The various applications of a control strategy designed according to this invention along with the various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiments. The drawings that accompany the detailed description can be briefly described as follows.